Plastic composition



Patented Oct. 21, 1924.

1,512,024 PATENT; OFFICE.-

I CARE I). HOCKER, OF EAST ORANGE, JERSEY, ASSIGNO'R T WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

rLAsrIo conro'srriond No Drawing.

To all whom it may concern:

Be it known that I, CARL- citizen of the United States, residing at East Orange, in the county of Essex, State of New Jersey, have'invented certain new and useful Improvements in Plastic Compositions, of which the following is a full,

clear, concise, and exact description.

This invention relates to plastic composi-.

l0 tions and more specifically, to molded insulating compositions which find extensive application in the electrical art.

One difiiculty which has been experienced in making molded articles has been that due to the brittleness of the final product. Hard rubber, phenol condensation products, and ceramic compositions have been limited in their applicatlon on account of this char-- processes a certain amount of distillation may take place. The acid and alcohol containing substancesmay be entirely separate and distinct compounds and be physically mixed together prior to the distillation, or

they may be in chemical combination. In the latter case, as the well known action of vegetable oils when heated, the subsequent heat treatment is commonly spoken of as polymerization or gelatinization.

' For exampIeI, thedesired product may be obtained in any of the three followingways: '1. Treatment of a free fatt acid or a mixture of free fatty acids wit a polyacid alcohol or a mixture of polyacid alcohols. 2. Treatment of a resin or varnish gum or mixture of resins or varnish gums with a polyacid alcohol or a mixture of polyacid alcohols.

3. Polymerization or elatinization of a 59 drying or semi-drying 011 or a mixture of drying or semi-drying oils.

'In the first of the above methods a physical mixture of acids which belong to the series of .so-called fatty acids and of polyacid alcohols which'are..derivab1e from a D. HooKER, a.

Application filed December 17, .1919. Serial No. 345,460.

parafline hydrocarbon by the substitution of hydroxyl groups for atoms of hydrogen, is heated togelatinization. .In order that it may be understood what acids are intended to be included as belonging to the fatty acids class, a word of explanation is considered to be necessary. Various text-books which contain matter relating to the chemical composition of such .substances, difier in their'classification of the fatty acids. As

acid is considered to include any and all classes embraced by the following outline: 1.;Acids of the aceticseries, CHIL O 2. Acids of the oleic series, C H O 3. .Acids of the series, fl I-I O which includes the open chain and cyclic acids.

4..Acids of the linoleic series, G I-I ,O

5. Acids of the clupandonic and the C I-I O series, 1

6. I-Iydroxylated and carboxylated acids of any of the above classes.

In the second method, the acid containingbodies. are resins orthe so-called varnish gums. They consist of two or three separate and distinct chemical compounds,

namely, the resin esters and their decomposition bodies, resins and resin acids. The adaptability of these compounds depends primarily on the presence of these resin acids. They are, for the most part of a complex constitution and of high molecular weight and contain one or more hydroxyl groups of carboxyl residues.

In the third method, only one substance is required to be used. It is in effect a chemical combination of compounds which belong to the general class referred toas being employed in the first method. Vegetable oils,

chemically speaking, consist of mixtures of glycerides, that is a mixture of the esters of glycerine which are formed by the treatment of glycerine with the fatty acids. In this latter case both constituents go to effect the desired result, while in the case of the resin,

ed to destructivedistillation until a gummy residue is obtained. The operation is refused in this specification, the term fatty 10( .the further addition of the alcohol is re- 40- erably mixed in just. prior 'to the pressing erably carried outinan iron receptacle so arranged that the fumes occasioned by heat found that in such a ca se when the pressure is released the mass will tend to spring back and occupy its original volume. If the composition'is held'withinthe mold and allowed 'to cool therein, under pressure, the difliculty experienced by theresiliency ofthe-material may be partially overcome.

As a further modification of the process, however, it has been found more desirable to continuethe heatingof the gelatinous product which results from the gelatinization or. polymerization until it is slightly carbonized. This is preferably accomplished by subjecting the composition to direct heat after having reduced it to comparatively small particles. A small amount of a free fatty acid, for example that derived from the saponification of tung oil, is then added in order to restore the binding properties lost by the charring. After thoroughly .incorporating the acid, the mass is then put into the mold and pressed. In this manner the resilient effect is reduced to such an extent that a highly satisfactory molded article may be-produced.

It has been found that the compositions may be used primarily as binders and comminutedinert material such as mica added thereto. If this material be used it is pref process.

An examination ofthe compounds formed from any of the three methods referred to herein, will show that they are similar in many physical and chemical properties. The following will serve to show this more clearly;'

'1. Similar in appearance.-

2. Physical phenomena'accompanying for-. mation of gelatinized products are similar.

' 3. Difl er in degree of resiliency, but all are resilient and springy at some temperature.

4. Insoluble in the common'solvents--even solvents or mixtures of them which will disiency is concerned. For example, the comsaid oi solve the oil or resin from which they are pound formed by using castor oil as a base is quite tenacious and flexible, while that. formed from shellac as a base is more or less brittle at ordinary temperatures. It appears to be a characteristic of the compounds which are formed when vegetable oils are usedas the basic material that they form more or less resilient and springy bodies at ordinary temperatures. On the other hand, the resin derivatives appear to be more brittl under the same conditions. When molded compositions are made from the oil base, for example, the pressure which is applied to the vheated mold must be continued for quite a length of time, and subsequently cooled to insure a product that will retain its shape after release from the mold. The derivative of the resin base, however, will, upon the application of heat readily become l homoge nous anduniform, and require only a minimum amount of pressure with heat to give. it a certain desired form which it will re tain after removal from the mold. Hence, it is possible by taking a certain amount of the oil derived compound and adding thereto a certain amount of the resin derived compound, to obtain a final product which shall possess predetermined properties, in so far as resiliency and brittlene ss is concrned.

While it has been stated herein that partial carbonization of the gelatinous product resulting .from the use of castor oil is desirable in order tosecure a satisfactory composition, it is not necessarily desirable in all cases. For example, if the base selected be the copal, no charring is required in order to effect the desired result.

What is claimed is:

1. A. molding composition comprisin a filler and the product obtained-by heating until partial carbonization has taken place a material capable of engendering organic acid and glycerine. v

2.. A molding composition comprising a filler, the product obtained by heating until partial carbonization has taken place a material capable of engendering organic acid and polyacid alcohol, and a substance to restore the binding properties lost by the charring of said compounds.

3. A molding composition comprising a filler, the product obtained by heating vegetable oil until partial carbonization has taken place, and a substance to restore the binding properties lost by the chewing of 4. The process of making a molded article which comprises gelatinizing vegetable oil, reducing the resiliency of the gelatinous product, adding thereto a filler, and pressing the whole into the desired shape.

5. The process of making a molded article which comprises mixing the gelatinous product derived from heating vegetable oil and thatderived from heating a. resin addfiller, the

'ing thereto a filler, and pressing the whole.

into the desired shape.

6. The process of making a molded article which comprises heating vegetable oil until partial carbonization takes place, adding a substance to restore the binding properties lost by the oil through charring, mixing therewith a filler, and pressing the product into the desired shape.

. 7. A molding composition comprising a product obtained by heating castor oil until partial carbonization has taken place, and a small amount of free fatty acid to restore binding properties lost by the charring of said 011.

8. Theprocess of making a molded article which comprises the destructive distillation of vegetab e oil until a, gummy residue is obtained, the application of pressure to the hot mass and the cooling of the mass while under ressure.

9. T e process of making a molded article which comprises heating a material capable ofengendering organ c acid and '01 acid alcohol, reducing the resiliency o 't e gelatinous product, adding thereto a filler, alllld. pressing the whole into the desired s ape.

10. The process of making a molded article which comprises gelatimzing a material apable of engendering fatty acid and lycerine, reducing the resiliency of the ge atinous product, adding thereto a filler, and pressing the whole into the desired shape.

11. The process of making a molded article which'comprises heating'a material capable of engendering orgamc acid and glycerine until partial carbonization has'taken place, adding thereto a filler, and; pressing the whole into the desired shape.

In witness whereof, I hereunto subscribe I my name this 10th day of December, A. D.

CARL n. HOCKER. 

